Abstract CT259: Pivotal Study of the LUM Imaging System for assisting intraoperative detection of residual cancer in the tumor bed of female patients with breast cancer

Abstract Background Breast-conserving surgery is a critical first step in treatment with the goal of removing all cancer cells while minimizing the removal of healthy tissue. 15% to 25% or more of lumpectomy patients have positive margins and require a second surgery to achieve negative margins and reduce the risk of local recurrences. These positive margins are poorly predictive (35% PPV) of cancer left in the cavity, so most second surgeries find no residual cancer. Better detection tools are needed to identify residual cancer in real time during the initial lumpectomy to reduce the number of second operations. LUM015 is a protease-activated fluorescent imaging agent that accumulates in tumor cells and tumor associated macrophages. The LUM Imaging System camera visualizes the intravenously injected LUM015 in the lumpectomy cavity via a hand-held wide field detector and proprietary tumor detection software. This imaging system was previously tested in multiple single-site studies and a large, prospective multi-site study that enrolled 234 patients and showed good ability to detect residual cancer in the lumpectomy cavity. Trial Design The current prospective, multi-center, randomized, blinded study was designed to demonstrate the clinical efficacy, system accuracy, and safety of the LUM Imaging System. It aims to identify residual cancer in the lumpectomy cavity to reduce the rates of positive margins. This study seeks to enroll women with primary invasive breast cancer (IBC), ductal carcinoma in situ (DCIS) or a combination of IBC/DCIS undergoing a lumpectomy for their breast malignancy. Approximately 310 women at 14 US medical centers will be enrolled. This study is powered by an event-driven design that requires 70 patients to be enrolled that have a ‘truth-standard positive' event, which is the identification of cancer in a protocol defined tissue type. To be eligible, patients must not have a history of allergic reaction to polyethylene glycol, intravenous contrast agents, or systemic therapies to treat their cancer. Use of blue dyes before imaging with the LUM System are not allowed. LUM015 is injected prior to the lumpectomy procedure. Surgeons perform standard of care (SOC) lumpectomy and perform blinded intraoperative imaging of the lumpectomy cavity with the LUM Imaging System in regions where SOC shaves will be taken. The patient is then randomized. If the random assignment is to the device arm, the surgeon is directed to excise margins that the LUM System indicates are positive for cancer. Pathologists are blinded to the type of tissue removed when conducting the pathology assessment. Patient reported outcome data is collected as a quality-of-life survey before and after the subject's lumpectomy. Additional detailed eligibility criteria are in the protocol. To date, 166 patients have participated in this trial. This trial is registered as NCT03686215. Citation Format: Jorge Ferrer, David Carr, Peter Blumencranz, Irene Wapnir, Donna Dyess, Shelly Hwang, Nayana Dekhne, Daleela Dodge, Beth-Ann Lesnikoski, Kelly Hunt, Patricia Clark, Stephanie Valente, M. Catherine Lee, Lynne Clark, Brian Schlossberg, Sean Madden, Alejandra Rodriguez, Kate Smith, Manna Chang, Barbara Smith. Pivotal Study of the LUM Imaging System for assisting intraoperative detection of residual cancer in the tumor bed of female patients with breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr CT259.